Driver of light emitting diode and light emitting device

This application claims the priority benefit of Taiwan application serial no. 112148960, filed on Dec. 15, 2023. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

The disclosure relates to a technology for inspecting the functionality of elements on a panel, and particularly to a driver of a light emitting diode (LED) and a light emitting device.

Displays have consistently held a prominent position in the consumer market. Apart from a liquid crystal panel, a liquid crystal display (LCD) requires a backlight module for light emission. Relevant elements are soldered onto a substrate (such as a plastic substrate, a glass substrate, a tape substrate, and so forth) utilized by the backlight module, and the elements include external passive elements, LED lamps, driving chips, and other elements.

Determining the presence of issues of abnormal circuit connections, such as false soldering, empty soldering, short circuits, open circuits, in the elements affixed to the substrate is challenging through visual appearance or alternative methods. Consequently, post-soldering inspection remains imperative to verify the normal functionality of these elements. Besides, the LED lamp or the driving chip on the backlight module commonly transmit display data according to a serial communication protocol. In instances where a driving chip exhibits circuit connection abnormalities, not only is the affected driving chip unable to display, but subsequent elements serially connected to the driving chip are also affected. In cases where a significant number of elements are connected in series to the faulty driving chip, ascertaining the integrity of these elements becomes unfeasible. Therefore, after the replacement of the faulty driving chip, the panel should be illuminated again, and a repeated inspection methodology is employed to ensure the normal functioning of subsequently serially connected driving chips.

The disclosure provides a driver of a light emitting diode (LED) and a light emitting device to assess potential connection abnormalities in relevant signal circuits across multiple stages of drivers at once by adopting a signal path structure corresponding to a test mode of the driver.

According to an embodiment of the disclosure, a driver of an LED includes a first receiver, a second receiver, a data controller, a transmitter, and a check controller. The first receiver receives a parallel data signal. The second receiver receives a serial data signal. The data controller is coupled to the first receiver. The transmitter is coupled to the data controller. The data controller obtains the parallel data signal through the first receiver and transmits the parallel data signal to a serial data output terminal through the transmitter to transmit the parallel data signal to a next-stage driver. The check controller is coupled to the first receiver and the second receiver, detects whether the parallel data signal is received through the first receiver and whether the serial data signal is received through the second receiver, and generates a driving signal of the LED based on the received parallel data signal and the received serial data signal to illuminate the LED.

According to an embodiment of the disclosure, a light emitting device includes a driving device. The driving device includes a first driver and a second driver. The first driver drives a first LED module and includes a first serial data input terminal, a first parallel data input terminal, and a first serial data output terminal. The first serial data input terminal is configured to receive serial data. The first parallel data input terminal is configured to receive parallel data. The second driver is coupled to the first driver and configured to drive a second LED module, and the second driver includes a second serial data input terminal, a second parallel data input terminal, and a second serial data output terminal. The second serial data input terminal is coupled to the first serial data output terminal of the first driver. The second parallel data input terminal is configured to receive the parallel data. When the driving device operates in a first mode, the first serial data output terminal of the first driver outputs the serial data, and when the driving device operates in a second mode, the first serial data output terminal of the first driver outputs the parallel data.

As such, in the driver of the LED and the light emitting device provided in one or more embodiments of the disclosure, each driver is equipped with a signal path structure corresponding to the test mode. This configuration involves transmitting the parallel data signal from a preceding-stage driver to the serial data input terminal of the next-stage driver, effectively converting the parallel data signal into the serial data signal for the next-stage driver. This mitigates the challenge of being unable to examine the driver at the end of a series of multiple stages of serially connected drivers due to potential circuit connection abnormalities in the serial-type data path. Accordingly, in one or more embodiments of the disclosure, the connection abnormalities in the relevant signal circuits across the multiple stages of drivers may be checked simultaneously by utilizing the signal path structure corresponding to the test mode of the driver, whereby the repetitive work hours required by operating staff during the inspection process may be reduced.

Several exemplary embodiments accompanied with figures are described in detail below to further describe the disclosure in detail.

is a schematic view of a light emitting deviceaccording to an embodiment of the related art. The light emitting devicemay serve as a backlight module of a display or as a display driving device of a light emitting diode (LED). The light emitting deviceincludes a plurality of drivers (e.g., drivers-˜-in) and LED modules (e.g., LED modules ch˜chin). Each of the LED modules ch˜chincludes at least one LED, and these LEDs may emit light of different colors. For instance, the LED modules ch˜chmay respectively have red, blue, green, and white LEDs or LED lamp strings. The light emitting deviceis a light panel integrated by controlling a light emitting brightness of the LED modules ch˜chthrough sequentially arranged multi-stage drivers-˜-, in series; through a light guide plate, a prism sheet, a diffusion sheet, and other similar elements (not shown in), the backlight module may emit light in a uniform manner to a liquid crystal panel. The drivers may be implemented in the form of driving chips.

The drivers-˜-depicted inare mainly controlled by two data, one is parallel data PDIS (also known as a parallel data signal), and the other is serial data SDIS (also known as a serial data signal). The parallel data PDIS and the serial data SDIS may be provided by a controller (not shown). A preceding-stage driver provides a next-stage driver brightness data or chip setting data in the serial data SDIS. For instance, the driver-receives the brightness data or the chip setting data at a serial data input terminal SDI and transmits these data to the next-stage driver-through a serial data output terminal SDO of the driver-; the driver-receives the brightness data or the chip setting data at its the serial data input terminal SDI and transmits these data to the next-stage driver-through a serial data output terminal SDO of the driver-, and the rest may be deduced therefrom. In other words, a transmission path of the serial data SDIS is a serial-type data path. A transmission path of the parallel data PDIS is a multidrop path, which is configured to allow the drivers-˜-to receive common setting data and provide synchronous data signals.

During the manufacture of the light emitting device, the path of the parallel data PDIS, the path of the serial data SDIS, and connection paths between the drivers-˜-are arranged on a substrate, and each of the drivers-˜-is soldered to a corresponding location on the substrate. Soldering elements onto the substrate may cause abnormal circuit connections; however, it is difficult to quickly and accurately determine where the circuit connection abnormality occurs when checking whether the drivers-˜-operate normally.

For instance, according to this embodiment, a pattern signal is provided as the parallel data PDIS and the serial data SDIS to check whether the drivers-˜-operate normally. Given that there are abnormal circuit connections at regions-and-indue to soldering, the driver-may normally receive the parallel data PDIS and the serial data SDIS and may operate normally. The driver-, however, does not operate normally because the driver-cannot receive the parallel data PDIS, and the driver-does not operate normally because driver-cannot receive the serial data SDIS. Nevertheless, since the path of the serial data SDIS is a serial-type signal path, and due to the damaged region-on the path of transmitting the serial data SDIS between the driver-and the driver-, the serial data SDIS is not be transmitted to the driver-, and therefore it is impossible to know whether the driver-operates normally.

If one intends to learn whether the driver-operates normally, it is necessary to first repair the abnormal circuit connections at the regions-and-inand then check the drivers-˜-again to clearly inspect whether the function of the driver-is normal. If the number of drivers serially connected in the light emitting deviceis significant, it may be necessary to repeatedly perform the above-mentioned checks during the inspection, so as to gradually complete the repair of each abnormal circuit connection in the light emitting device.

Therefore, according to an embodiment of the disclosure, a signal path structure corresponding to a test mode is provided, and the signal path structure may allow an effective detection of whether the driver has abnormal circuit connections without needing of repeated checks as shown in. Specifically, according to this embodiment of the disclosure, the parallel data signal in the preceding-stage driver is transmitted to the serial data input terminal of the next-stage driver as the serial data signal of the next-stage driver, thereby avoiding the inability to check the driver at the end of the multiple stages of serially connected drivers due to the abnormal circuit connections in the serial-type data path. As such, an inspector may directly replace or repair the driver with connection issues in the light emitting device, thereby facilitating the repair of the entire light emitting device.

is a functional block view of a driver-according to an embodiment of the disclosure. The driver-may be a driving chip of a light emitting device in a display, and the light emitting device may be controlled by multiple stages of serially connected drivers (such as a driver-and a next-stage driver-) to control an LED module ChN. Here, N represents a positive integer. The driver-and its elements may be implemented in the form of hardware circuits or firmware devices, such as microprocessors, logic circuits, field programmable gate arrays (FPGA), and so on.

The driver-includes a first receiver, a second receiver, a data controller, a transmitter, and a check controller. The first receiverreceives the parallel data signal PDIS at a parallel data input terminal PDI of the driver-. The second receiverreceives the serial data signal SDIS through a serial data input terminal SDI of the driver-. The data controlleris coupled to the first receiver. The transmitteris coupled to the data controller. The driver-further includes a display controller. The display controlleris coupled to the data controller. In this embodiment, the first receiverand the second receiverare first-in-first-out (FIFO) receivers. The transmitterin this embodiment is a first-in-first-out (FIFO) transmitter.

In this embodiment, the driver-has a first mode (e.g., a work mode) and a second mode (e.g., the test mode). These two modes may be switched by the data controllerafter receiving the parallel data signal PDIS with a specific data arrangement. In another embodiment, the data controllertransmits the data from the first receiveror the second receiverto the next-stage driver-via the transmitteraccording to a mode signal. In one embodiment, the data controllertransmits the received serial data signal SDIS to the serial data input terminal SDI of the next-stage driver-in the first mode, and the data controllertransmits the received parallel data signal PDIS to the serial data input terminal SDI of the next-stage driver-in the second mode.

In the test mode, the check controlleris enabled, and the display controlleris disabled; in the work mode, the check controlleris disabled, and the display controlleris enabled. In the work mode, the second receiveris coupled to the data controller. In the work mode, the data controllerreceives the serial data SDIS through the second receiverand transmits display data in the serial data SDIS to the display controller. The display controllergenerates a driving signal SDRV of the LED based on the display data to illuminate the LED module ChN. In other words, in the work mode, the serial data SDIS received by the second receiverare transmitted to the data controllerbut not transmitted to the disabled check controller.

In this embodiment, the test mode of the driver-has a corresponding signal path structure which allows a one-time inspection of whether there is a connection abnormality in the relevant signal circuits of multiple stages of drivers. Specifically, in the test mode, the data controllerobtains the parallel data PDIS via the first receiverand transmits the parallel data PDIS to the serial data output terminal SDO of the driver-through the transmitterto transmit the parallel data PDIS to the next-stage driver-. The data path is shown by an arrow. The next-stage driver-receives the signal provided by the driver-(the preceding-stage driver) as the serial data in the next-stage driver-at the serial data input terminal of the next-stage driver-. In other words, in the test mode, the serial data in the next-stage driver are the same as the parallel data in the preceding-stage driver. The parallel data PDIS in this embodiment have a check pattern signal (e.g., a preset disturbance signal and a check code for performing the inspection).

The check controllerdetects whether the parallel data PDIS are received through the first receiver(as shown by an arrowin), and the check controllerfurther detects whether the serial data SDI are received via the second receiver(as shown by an arrowin). When the check controllerdetects and receives the serial data SDI, such indicates that the connection between the serial data output terminal of the preceding-stage driver relative to the driver-and the serial data input terminal SDI of the driver-is normal, and there is no abnormality in the circuit connection, or the connection between a signal source of the serial data SDIS and the serial data input terminal SDI of the driver-is normal, and there is no abnormality in the circuit connection. When the check controllerdetects and receives the parallel data PDIS, it indicates that the connection between a signal source of the parallel data PDIS and the parallel data input terminal PDI of the driver-is normal, and there is no abnormality in the circuit connection.

When the check controllerdetects and receives both the parallel data PDIS and the serial data SDIS, such indicates that there is no abnormality in the connection between the relevant pins or circuits of the driver-(e.g., the connection between the arrowsand). Therefore, the check controllergenerates the driving signal SDRV of the LED based on the parallel data PDIS and the serial data SDIS to illuminate the LED module ChN, which is coupled to and controlled by the check controller, so as to allow the inspector to visually ascertain the state of the driver-.

By contrast, if the check controllerdoes not detect either or both of the parallel data PDIS and the serial data SDIS, the check controllerdoes not illuminate the LED module ChN. The inspector may then ascertain that there is an issue occurring in the corresponding driver of the non-illuminated LED module ChN, and the issue requires further processing.

is a schematic view of a light emitting deviceaccording to an embodiment of the disclosure. The light emitting devicemay serve as a backlight module of a display or as a display driving device of an LED. The light emitting deviceincludes at least one driver (e.g., drivers-˜-) and at least one LED module (e.g., the LED modules ch˜chrespectively corresponding to the drivers-˜-). The circuit structure of each driver-˜-provided in this embodiment as shown inis the same as the driver-in. The driver-receives an external serial data SDIS and transmits the serial data SDIS to the next-stage driver-and so on in the work mode. In the test mode, the drivers-˜-transmit the parallel data to the serial data input terminal of the next-stage drivers-˜-.

For a more detailed explanation, the signal path structure corresponding to the test mode configured in each driver may be applied to perform a one-time inspection of whether there is a connection abnormality in the relevant signal circuits of multiple stages of drivers.mainly depicts the multiple stages of interconnected drivers-˜-. Here, arrows-to-marked on the drivers-to-serve to illustrate the data path between the parallel data input terminal PDI and the serial data output terminal SDO in each driver.

With reference to, when the drivers-to-are all set in the test mode, given that there is a circuit connection abnormality at regions-and-indue to soldering, and internal circuits of the drivers-to-operate normally without any abnormalities, at this time, the driver-operates normally because the driver-may properly receive the parallel data PDIS and the serial data SDIS, and the data path marked by the arrow-allows normal passage. The driver-cannot receive the parallel data PDIS due to the damaged region-, and the data path marked by the arrow-cannot allow the normal passage. Therefore, the check controller in the driver-does not illuminate the LED modules ch˜chcorresponding to the driver-.

The driver-cannot receive the parallel data PDIS from the next-stage driver-due to the damaged regions-and-, and thus the check controller in the driver-does not illuminate the LED modules ch˜chcorresponding to the driver-. However, the circuit connection abnormalities at the regions-and-do not affect the data path marked by the arrow-in the driver-. That is, the data path marked by the arrow-in the driver-allows normal passage, and thus the check pattern signal in the parallel data PDIS (e.g., a preset disturbance signal and a check code for performing the inspection) is normally transmitted to the driver-. Accordingly, the driver-normally receives the parallel data PDIS and the serial data SDIS and operates normally, and the circuit connection abnormality at the region-does not affect the receipt of the check pattern signal.

is a flowchart of a method of driving an LED according to an embodiment of the disclosure. The driving method depicted inis applicable to the driver-in. With reference toand, in step S, the driver-inis set to the test mode, and the driver inincludes the first receiverand the second receiver. The parallel data PDIS with a specific data arrangement may be applied to set the driver-into the test mode.

In step S, in the test mode, the data controllerin the driver-depicted inobtains the parallel data PDIS through the first receiverand transmits the parallel data PDIS to the next-stage driver-through the transmitter. In step S, the check controllerindetects whether the parallel data PDIS are received through the first receiverand whether the serial data SDIS are received through the second receiver. In step S, the check controllerilluminates the LED module ChNbased on the received parallel data PDIS and the received serial data SDIS. Details of the steps Sto Smay be referred to as those provided in the previous embodiments.

andare schematic views of a light emitting deviceaccording to another embodiment of the disclosure.may serve to explain the operation of each driver in the light emitting devicein the first mode (work mode).illustrates the driving device in the light emitting device(e.g., the first driver-, the second driver-, and the third driver-). In the first mode (work mode), the serial data input terminal SDI of the first driverreceives the serial data SDIS from a controller (not shown) and transmits the received serial data SDIS to the serial data input terminal SDI of the second driver-through the serial data output terminal SDO (as shown by an arrowrepresented in dash lines). As mentioned earlier, the second driver-transmits the serial data to a post-stage driver, such as the third driver-. The transmission path of the parallel data PDIS is a multidrop path configured to allow the first to third drivers-˜-to receive common setting data and provide synchronous data signals, as shown by an arrowrepresented in dash lines.

may serve to illustrate the operation of each driver when the light emitting deviceoperates in the second mode (test mode). In the test mode, the signal received by the serial data input terminal SDI of the first-stage driver (such as the first driver-) comes from the serial data SDIS. Except for the first-stage driver (the first driver-), the signal received by the serial data input terminal SDI of each driver comes from the data received by the parallel data input terminal PDI of the preceding-stage driver. For instance, the signal received by the serial data input terminal SDI of the second driver-comes from the data received by the parallel data input terminal PDI of the first driver-, as shown by an arrowrepresented in dashed lines. Simply put, according to the present embodiment, the control circuit in the driver may be applied to switch between the work mode and the test mode. When operating in the work mode (first mode), each driver (e.g., the drivers-˜-) outputs the data received at its serial data output terminal SDO by its serial data input terminal SDI. However, in the test mode (second mode), the driver outputs the data received at its serial data output terminal SDO by its parallel data input terminal PDI.

To sum up, in the driver of the LED, the driving method, and the light emitting device provided in one or more embodiments of the disclosure, each driver is equipped with the signal path structure corresponding to the test mode. This configuration involves transmitting the parallel data signal from the preceding-stage driver to the serial data input terminal of the next-stage driver, effectively converting the parallel data signal into the serial data signal for the next-stage driver. This mitigates the challenge of being unable to examine the driver at the end of a series of multiple stages of serially connected drivers due to potential circuit connection abnormalities in the serial-type data path. Accordingly, in one or more embodiments of the disclosure, the connection abnormalities in the relevant signal circuits across the multiple stages of drivers may be checked simultaneously by utilizing the signal path structure corresponding to the test mode of the driver, whereby the repetitive work hours required by the operating staff during the inspection process may be reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and ther equivalents.